AEROSPACE ENGINEERING 9.1 Definition
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Page 1 of 8 AEROSPACE ENGINEERING 9.1 Definition: Aerospace Engineering is the primary branch of engineering concerned with the research, design, development, construction, testing, science and technology of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering. Aeronautics deals with aircraft that operate in Earth's atmosphere, and astronautics deals with spacecraft that operate outside the Earth's atmosphere. Founded by dreamers and pioneers such as Konstantin Tsiolkovsky, the field reached its maturity with launching of first artificial satellite, first man in space and first step on the Moon. Aerospace Engineering deals with the design, construction, and study of the science behind the forces and physical properties of aircraft, rockets, flying craft, and spacecraft. The field also covers their aerodynamic characteristics and behaviors, airfoil, control surfaces, lift, drag, and other properties. Aeronautical engineering was the original term for the field. As flight technology advanced to include craft operating in outer space, the broader term "aerospace engineering" has largely replaced it in common usage. Aerospace engineering, particularly the astronautics branch, is often referred to colloquially as "rocket science", such as in popular culture. Overview Flight vehicles are subjected to demanding conditions such as those produced by changes in atmospheric pressure and temperature, with structural loads applied upon vehicle components. Consequently, they are usually the products of various technological and engineering disciplines including aerodynamics, propulsion, avionics, materials science, structural analysis and manufacturing. The interaction between these technologies is known as aerospace engineering. Because of the complexity and number of disciplines involved, aerospace engineering is carried out by teams of engineers, each having their own specialised area of expertise. The development and manufacturing of a modern flight vehicle is an extremely complex process and demands careful balance and compromise between abilities, design, available technology and costs. Aerospace engineers design, test, and supervise the manufacture of aircraft, spacecraft, and missiles. Aerospace engineers develop new technologies for use in aviation, defense systems, and space. Page 2 of 8 9.2 History One of the most important people in the history of aeronautics, Cayley was a pioneer in aeronautical engineering and is credited as the first person to separate the forces of lift and drag, which are in effect on any flight vehicle. Much of the early work leading to the airplane involved gliders, and the 19th century saw dozens of glider experiments. Sir George Cayley expressed the principles of heavier-than-air flight starting in 1804, and in 1856, Jean-Marie Le Bris flew the first manned glider that climbed higher than its launch point. Le Bris did this by having a horse tow the glider along a beach. The lack of a suitable engine thwarted many early efforts at powered, heavier-than- air flight. The first successful powered flight is credited to Orville and Wilbur Wright. The brothers incorporated the concepts of lift, weight, drag and thrust from a suitably powerful engine, and three-axis control of pitch, roll and yaw. In doing so, the inventors created the first airplane able to take off and climb on its own power, fly for a significant distance and make a controlled landing. After the invention of fixed-wing airplanes, came the first rotary-wing aircraft, which include autogyros and helicopters. Based on principles first demonstrated in Chinese flying toys dating to 400 B.C., the idea of rotary-wing aircraft inspired many inventors to attempt vertical flight with rotating propellers. A number of small models powered by springs and rubber bands were built, but again, the first true helicopter had to wait for a suitably powerful engine. Helicopter and autogyro designs progressed incrementally over the next few decades. Juan de la Cierva is credited with inventing the autogyro, a type of aircraft with fixed wings that uses a rotor for lift and a propeller for thrust. His advancements in rotary design led directly to the first modern helicopter, which is generally attributed to Igor Sikorsky in 1942. Early innovators of powered, lighter-than-air craft included Jules Henri Giffard, who in 1852 flew the first steerable steam-powered airship; Charles Renard and Arthur Constantin Krebs, who in 1884 flew the first powered airship to return to its starting point; and Ferdinand von Zeppelin who built and flew the first rigid airship, in 1900. The first definition of aerospace engineering appeared in February 1958. The definition considered the Earth's atmosphere and the outer space as a single realm, thereby encompassing both aircraft (aero) and spacecraft (space) under a newly coined word aerospace. In response to the USSR launching the first satellite, Page 3 of 8 Sputnik into space on October 4, 1957, U.S. aerospace engineers launched the first American satellite on January 31, 1958. The National Aeronautics and Space Administration was founded in 1958 as a response to the Cold War. The other side of aerospace engineering is rocketry and spacecraft. The most famous pioneers in this field were Robert Goddard, who constructed and successfully launched the first liquid-fueled rocket; Werner von Braun, who developed the first ballistic missile and went on to become the first director of NASA's Marshall Flight Center; and Konstantin Tsiolkovsky, who is considered the Russian father of rocketry. Several astronauts were aerospace engineers, including Kalpana Chawla, the first Indian-born woman in space, who died in the space shuttle Columbia disaster; and Neil Armstrong, the first man on the moon. Armstrong himself once said: "I am, and ever will be, a white socks, pocket protector nerdy engineer." Other well-known aerospace engineers include Boback Ferdowski, the "Mohawk Guy," who serves as flight director of NASA's Mars Curiosity rover mission, and Burt Rutan, whose company, Scaled Composites, designed SpaceShipOne, the first nongovernment manned spacecraft. 9.2 What does an aerospace engineer do? Aerospace engineers design aircraft, spacecraft, satellites and missiles, according to the BLS. In addition, these engineers test prototypes to make sure that they function according to plans. These professionals also design components and subassemblies for these craft; those parts include engines, airframes, wings, landing gear, control systems and instruments. Additionally, engineers may perform or write the specifications for destructive and nondestructive testing for strength, functionality, reliability, and long-term durability of aircraft and parts. Here are some recent developments of note in aerospace engineering: Many aerospace innovations are making their way into automobile technology, such as thermoelectric generators, which use heat to make electricity, and hydrogen fuel cells, which take hydrogen gas and mix it with oxygen to generate useful electricity, heat and water. A team of engineers has developed an algorithm that can convert brain waves into flight commands. The team hopes to make mind-controlled Page 4 of 8 aircraft a reality. Researchers are deliberately setting fires on the International Space Station to study "cool-burning" flames, which could lead to more- efficient car engines that contribute less pollution to the environment. Today's aerospace engineers still work with the basic concepts of aerodynamics, and must also have a working knowledge of aircraft power plants such piston engines, turbo props and jets, the BLS said. Astronautical engineers must also understand additional concepts, such as spacecraft propulsion systems, which include solid- and liquid-fuel rockets, along with ion drives. Manned missions require life support systems to provide air, food, water, temperature control and waste handling, so spaceflight engineers must also be familiar with these concepts. Aerospace engineering requires in-depth skills and understanding in physics, mathematics, aerodynamics and materials science. These professionals must be familiar with advanced materials such as metal alloys, ceramics, polymers and composites, the BLS said. This knowledge allows engineers to predict the performance and failure conditions of designs before they are even built. More and more, aerospace engineers rely on computer-aided design (CAD) systems for quick and easy drafting and modification of designs and 3D visualization of finished parts and assemblies. Computer simulations have become essential for performing virtual testing of engines, wings, control surfaces, and even complete aircraft and spacecraft under all possible conditions they might encounter. According to Robert Yancey, vice president of Aerospace Solutions at Altair Engineering, Inc., "Simulation is having a greater impact on defining concept designs. This is requiring design engineers, who traditionally do not have skills in simulation, to start to develop some competency in simulation." Computer simulations have greatly reduced the dangers to test pilots and the cost of failed missions. 9.3 Where do aerospace engineers work? Aerospace engineers generally work in professional office settings. They may occasionally visit manufacturing and testing facilities where a problem or piece of equipment needs their personal attention, according to the BLS. Aerospace Page 5 of 8 engineers work mostly